The present invention relates to scanning electron microscopes and CD measurement calibration standard specimens, and particularly to a scanning electron microscope and CD measurement calibration standard specimen suited to measure dimensions of fine patterns that are formed exposed on a semiconductor wafer.
Recently, the dimensional accuracy of patterns formed on a semiconductor wafer has been reduced up to less than 100 nm, and the scanning electron microscope has been generally used as a pattern-dimension managing tool. There are various different needs for the performance of the apparatus, and the chief ones will be improvements in resolution/static repeatability accuracy, and dimension-measurement calibration precision. The demanded dimension-measurement calibration precision is one nm or below. Under these circumstances, an example of dimension-measurement calibrating members is described as a dimension-measurement calibration standard specimen in JP-A-7-071947. In addition, another example of the dimension-measurement calibration standard specimen is disclosed in JP-A-8-031363. Moreover, an example of the critical dimension (CD) measurement calibration second-standard specimen is given in JP-A-2003-279321.